import java.util.Random;

public class PalyTest {
    public static void main(String[] args) {
        String s = "你就是狗"  ;
        Random random = new Random();
        String a =  "a" ;
        for (int i = 0; i <4 ; i++) {
            char c = s.charAt(random.nextInt(s.length()));

            a += c +"" ;
        }
        System.out.println(a.substring(1));
        System.out.println("你好世界！");
    }
}
